Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock Voting	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Retained Earnings
Beginning balance (in shares) at Mar. 31, 2019		119,760,132			42,149,771
Beginning balance at Mar. 31, 2019	$ 2,065,433	$ 120	$ 2,828,922	$ (2,639)	$ (1,119,063)	$ 358,093
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(29,343)					(29,343)
Unrealized net investment losses	35			35
Unrealized net losses on derivative financial instruments	(19)			(19)
Cumulative translation adjustments	(561)			(561)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		362,886
Issuance of common stock pursuant to vesting of restricted stock units	0	$ 0
Stock-based compensation expense for restricted stock units granted to employees	12,079		12,079
Repurchase of treasury stock (in shares)					1,418,949
Repurchase of treasury stock	(36,189)				$ (36,189)
Ending balance (in shares) at Jun. 30, 2019		120,123,018			43,568,720
Ending balance at Jun. 30, 2019	2,011,435	$ 120	2,841,001	(3,184)	$ (1,155,252)	328,750
Beginning balance (in shares) at Mar. 31, 2020		122,006,077			49,785,171
Beginning balance at Mar. 31, 2020	1,937,919	$ 122
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(17,420)					(17,420)
Unrealized net investment losses	(74)			(74)
Unrealized net losses on derivative financial instruments	40			40
Cumulative translation adjustments	953			953
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		347,427
Issuance of common stock pursuant to vesting of restricted stock units	0	$ 0
Stock-based compensation expense for restricted stock units granted to employees	11,502		11,502
Repurchase of treasury stock (in shares)					113,163
Repurchase of treasury stock	(3,103)				$ (3,103)
Ending balance (in shares) at Jun. 30, 2020		122,353,504			49,898,334
Ending balance at Jun. 30, 2020	$ 1,929,817	$ 122	$ 2,903,055	$ (2,241)	$ (1,309,038)	$ 337,919